(defvar *grid-resolution* 10)

(defun make-map (width height)
  (make-array (list width height) :initial-element ()))


(defun get-node-for-coordinates (x y)
  (list (floor (/ x *grid-resolution*)) (floor (/ y *grid-resolution*))))


(defun place (map x y thing)
  (let* ((node-coordinates (get-node-for-coordinates x y))
	(node-x (first node-coordinates))
	(node-y (second node-coordinates)))
	  
    (setf (aref map node-x node-y) (append (aref map node-x node-y) thing))))
  
  